The subject matter of the present invention is a method for detecting hydrogen peroxide by means of nuclear magnetic resonance and apparatus for performing said method. The method and apparatus can preferably be used for detecting hydrogen peroxide e.g. in luggage of flight passengers or in parcels or the like.
The detection of explosives or chemical precursors of explosives has an increasing importance due to the increase in terrorist attacks. It is particularly important on airports for checking the luggage of passengers and in freight business for the supervision of parcels. Several techniques, which are e. g. based on X-rays have been tested and implemented in the past. However, in particular X-ray scans of luggage and hand luggage does usually not give any evidence whether a liquid detected is harmless like e. g. water, milk and the like, or whether it is an explosive or a precursor of an explosive like hydrogen peroxide. In the past nuclear magnetic resonance techniques have been tried out. In particular spectroscopic nuclear magnetic resonance techniques, which usually allow a clear distinction of the respective sample, have been tried out. Until now these techniques have been disregarded by the market as the time necessary to perform the respective measurements is quite long and the operative efforts for obtaining a high enough resolution are demanding. Other techniques, like nuclear quadruple resonance (NQR) have been tried out, but they are not applicable for liquid samples. Furthermore, the use of spectroscopic data to detect explosives has been rejected by the market until now due to the high investments to be made mainly for hardware. Furthermore, a spectroscopic database for comparing measurement results with known spectra would be necessary.
Other techniques like dielectric measurements have been tried and implemented. Nevertheless even this fails e. g. for the identification of hydrogen peroxide (H2O2) from water because both show similar dielectric permitivities.